On July 21st 1969, the world gathered around TV sets and collectively held their breath as Neil Armstrong declared his famous words, "That's one small step for man. One giant leap for mankind," and set foot on the lunar surface for the first time.

It's a moment in history that's etched in the memories of people who saw it.

It has since transcended the decades to still be a defining moment in the world's modern history.

On that cold, squally day in central west NSW, the Parkes Radio Telescope, 'the Dish', played an integral role in getting the television pictures of man first walking on the moon to the world.

To cover the landing, NASA was set to use a telescope at Goldstone in California as the main receiver, with Parkes and Honeysuckle Creek near Canberra set to be backups.

The Parkes Telescope was chosen due to its size (being 64m in diameter, it had seven times the sensitivity for collecting signals).

"NASA wanted to have three stations equally spaced, so as the Earth rotated, they could have continuous coverage," says John Sarkissian, an Operations Scientist for the CSIRO based at the Dish.

"The Parkes Radio Telescope was recognised as a world leader in radio astronomy. Within the [astronomy] community, everybody knew that they were the go-to country."

On the day, the Dish had to overcome a number of significant hurdles in order to play the critical role that it did.

"The conditions at the time here were terrible," says John.

"Just moments before the moonwalk began a violent wind squall hit the telescope. The Dish was fully tipped-over at its most vulnerable when it was hit by two gusts exceeding 110km/h, and that actually made the telescope slam back against its zenith axis pinions causing the tower to shudder and sway.

"John Bolton, the Director of the observatory at the time, ordered his men to stay on the Dish, and just as Buzz Aldrin switched on the TV cameras, the winds abated and they received the signals.

"The astronauts may very well have been on the Sea of Tranquillity on the moon, but it was most definitely the ocean of storms here at Parkes at the time."

For the first eight minutes of the broadcast NASA switched between the pictures that were being received by Parkes, Honeysuckle Creek and Goldstone, before finally settling on using Parkes' signal for the rest of the two-and-a-half hour moonwalk.

The other significant challenge faced by the Parkes team involved the timing of the moon rise above NSW and the start of the moonwalk.

Due to a change in the mission schedule, the moonwalk was to begin later than originally planned at 4.20pm AEST, meaning Parkes was to become the primary receiving station as the moon would've set in the USA.

Just before 1pm the Parkes scientists thought of a solution to still be able to cover the landing.

"John Bolton realised that if they positioned the [second, weaker] receiver just right, they could actually pick up the signal," says John.

"Just as Buzz Aldrin switched on the TV camera, they were able to pick up the signal.

"What started off with Parkes perhaps not getting any pictures, ended up with them getting the entire picture and the majority that the world saw. And all this happened during a wind squall."

John says he's proud to work at the Dish and be surrounded by its rich history.

"It was a great moment in the history of the Parkes Telescope. We allowed the world to witness that remarkable event with the greatest possible clarity, and at the time, the rest of the world had no idea what the conditions were like here.

"When Armstrong said, 'It's a giant leap for mankind,' he meant it, and the world understood it as that," he says.